What two numbers add to 13 but multiply to negative 12?

9514 1404 393

  13.8654599313 and -0.8654599313

Step-by-step explanation:

If one of the numbers is x, then the other is 13-x, and their product is ...

  x(13 -x) = -12

  x^2 -13x = 12 . . . . multiply by -1 and simplify

  x^2 -13x +6.5^2 = 12 +6.5^2 . . . . complete the square

  (x -6.5)^2 = 54.25

  x -6.5 = √54.25

  x = 6.5 +√54.25 ≈ 13.8654599313

and the other number is ...

  13 -x = 13 -13.8654599313 = -0.8654599313

The two numbers are 13.8654599313 and -0.8654599313.

x =±sqrt(1/3)

step-by-step explanation:

x+4/6x=1/x

multiply each side by 6x to get rid of the fractions

6x*(x+4/6x)=1/x*6x

distribute

6x^2 +4 = 6

subtract 4 from each side

6x^2 +4-4 = 6-4

6x^2 =2

divide by 6

6x^2/6 = 2/6

x^2 = 1/3

take the square root of each side

sqrt(x^2) = ±sqrt(1/3)

x =±sqrt(1/3)

i think it would be 42cm